Process for making acetyl-cellulose plastics and solvents thereof.



STATES PATENT OFFICE.

WILLIAM G. LINDSAY, F CALDWELL, NEW JERSEY, ASSIGNOR TO THE GELLULOID COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

1,041,1 13. No Drawing.

Specification of Letters Patent.

Application filed November 6, 1911. Serial No. 658,784.

Patented Oct. 15,1912.

To all whom it may concern:

Be it kilown that I, WILLIAM G. LINDSAY, a citizen of the United States, residing in Caldwell, county of Essex, State of 'New Jersey, have invented a certain new and useful Process for Making Acetyl-Cellulose Plastics and Solvents Thereof, of which the following is a specification.

The .various compositions t which the present invention relates, are employed in the arts, generally as imitations of natural substances, sometimes in their original finished form with -or without incorporated colors, and sometimes as films which are used for photographic and other purposes.

Although the final or useful form of the different compounds of acetyl cellulose is that of, a solid or driedmaterial, the difierent processes of conversion into this final solidnform involve, as is well understood, the employment of solutions or mixtures of varying consistency as' to plasticity, stillness ,or fluidity, depending generally upon the proportion and kind of solvent used to 'the amount of the original base-acetyl cellulose.

'It has-Ion been known that .camphor A mixed with nitrocellulose upon the addition of ethyl alcohol to the mixture becomes" a solvent of the nitrocellulose! I have found, however, that when that process is applied to acetyl cellulose no solvent action takes place in the cold, and the object of my in vention was to find substances which, when added to the'ac'etyl cellulose would, u on the subsequent addition oi ethyl: alcohol exert a solventaction'upon the cellulose and produce a plastic mass which could be worked in a .manner analogous 'to nitrocellulose camphor. compounds.

I have discovered that not all of the socalled'camphor substitutes possess this property when used with acetyl cellulose, and in the course of my experiments I have found that camphor substitutes may, be grouped into three classes with respect to their solvent action on acetyl cellulose, namely:-

Class A: Those substances which are nonsolvents when melted, or when dissolved in,

either ethyl or-methy'l alcohol in the cold, or room temperature; such as triphenylphosphate, tncresylphosphate, and naphthalene.

Class B; Those substances which become solvents when melted, but are non-solvents when dissolved in ethyl alcohol at room temperature; such as camphor, tetra-chlorethyl acetanilid, and trichlormethyl acetanilid.

Class C: Such substances as become solvents when melted and also become solvents when dissolved in methyl or ethyl, alcohol in equal parts by weight at room temperature; such as toluol-sulphonamid, ethyl para toluol sulphonamid,-' benzene sulphonamid, ethyl acetanilid, and methyl acetanilid.

I have also discovered that in makingflowable solutions from my new compounds, I can employ substances other thanthose mentioned, and I have. accordingly divided this application into four divisions, each ,forming the subject ofa separate applica-- tion and designated by the letters A, B, C, and D, respectively.

In order to carry out the new process which forms the subject matter of this application (Division B), as one example, I

incorporate 100 parts of an acetyl cellulose whichis soluble in acetone with 20 to 50 parts of ethyl para toluol-sulphonamid'by suitable grinding and mixing, as is the practice in the nitrocellulose art. To such mixture I add from 40 to'100 parts of ethyl or of methyl alcohol, or a mixture of the two, and after thorough incorporation by stirring, the mixture is allowed to remain at room temperature in a closed vessel for from 5 to 24 hours, or longer, the length of time-depending upon the physical form of the acetyl cellulose used; that is, whether it is finely or coarsely ground. In the course of time the mixture will have become converted into a more or less stifi' gelatinated mass. It can then be worked up on rolls or' a kneading machine, according to the practice which is common in the 'mtrocellulose-camphor plastic art, and the resulting product may. then be molded or passed through the stuffing machineas in the case of nitrocellulose-camphor compounds.

p I have found that a mixture composed of1 part by weight each of ethyl alcohol and ethyl para toluol-sulphonamid is a more powerful solvent than a mixture of 2 parts b'y weight of ethyl alcohol and 1 part by weight ofethyl para toluol-sulph'onamid. If the alco. .hol is iucreasedheyond this proportion the lulose into a gelatinous mass, but the application of heat will restore to a certain ex tent thesolvent action of a solvent mixture which is otherwise too weak. A proportion of 1.5 parts of ethyl or methyl alcohol to 1 part of ethyl para toluol-sulphonamid also producesvery satisfactory results as a gelatmating a ent for acetyl cellulose.

Instea of the ethyl. para toluolesulphonamid I can use benzene-sulphonamid, and also ethyl acetanilid and related derivatives.

In order to produce flowable solutions in the cold from the gelatinous mass made ac? cording to the process above described and solutions which are suitable for filtering, etc, I have found that suitable solvents or diluents for such purposes are produced by incorporating with the mass, mixtures of either ethyl or methyl alcohol with the followin liquids in the proportions hereinafter descri ed; These liquids are chloroform, epichlorhydrin, acetodichlorhydrin, dichlorethylene, ethylene-chlorid, trichlorhydrin,

pentaehlorethane, acetochlorhydrin,. acetylene-tetrachlorid, chloracetate of ethyl, acctone, ethylacetate, and 'di-acetochlorhydrin.

A mixture produced by combining one of the above liquids with an equal volume of methyl or of ethyl alcohol, or a mixture of the two, willproduce a solvent for acetyl.

cellulose of the acetone soluble variety. I have discovered, also, that when the proportion of methyl or ethyl alcohol is increased beyond the pro ortion to produce a solvent mixture, the a dition of a camphor substitute of Class C 'reestablishes the solvent action.

In order to convert the gelatinous mass "mass I add from l-to 4 parts of this compound solvent, or suflicient to, produce product of the desired fluidity, and incorporate it by mixing, kneading, stirring or malaxating. After filtration or other treat ment, the solution of .acetyb cellulosethns produced is-worked up in the usual mannerby evaporating the excess of solvent and further kneading, pressing, etc., the re-.

sultant mass. ere, again, I have found that if the solvent is too weak, .the -application of heat will restore the solvent action;

If it is desired to produce a non-inflammable acetyl cellulose plastic compound WlllCll is made according to the process above described, I have found that this can be done by incorporating with the product of thatprocess such camphor substitutes of Class A above set forth as triphenylphosph'ate which efi'e-ct non-inflalmnability in the resultant mass. That is, the inflammabi'lity of the plastic masses made by the use of camphor substitutes of Class C can bereduced and overcome by incorporating such camphor substitutesas triphenylphosphate practices wellknown to the nitrocellulose art. If it is desired to produce a more fluid solution, the addition of 1 to t parts of a mixture consisting of 7 0 parts by volume of ethyl or methyl alcohol and 30 parts by volume of diclllorethylene, ethylenechlorid or chloroform, is added. It will thus be seen that the question of proportions enters very largely into the successful practice of the processes and the compositions of the new solvents described in this specification.

In order to distinguish the different branches of the invention or inventions described in this specification, I have, as

stated, divided the subject matter into four separate applications with claims corres onding accordingly and in this application Division B) I claim as follows: 1

1 The process of making plastic compounds of acetyl'cellulose consisting in ((1) incorporating with an acetyl cellulose soluble in acetone one part of the group of the hereinbeforedescribed substances (triphenyl phosphate, ,tricresyl phosphate) and one or more of the substances named in Class C herein (toluol-sulphonamid, ethyl para toluol-sulphonamid, benzene-sul honamid, ethyl-'acetanilid, methyl acetanihd) (2) adding one or more of the group of the hereinbefore-described alcohols (ethyl alcohol, methyl alcohol); (3) allowing the mix- ,ture to stand at room. temperature in a closed vessel until it has become a gelatinated mass; (4) working such'mass on rolls orin a heated press, or'otherwise; substantially as described.

2. The process of making plastic compounds of acetylcellulose, consisting in (1) incorpprating'with an ace lcellulose soluble in acetone one or more of the-grou of thehereinbefore described substances triphenyl phosphate, tricresyl phosphate) and one -or more of the substances specified in Class C herein (toluol-sulphonamid, ethyl .para toluol-sulphonamid, benzene sul honarnid, ethylacetanilid, methyl acetanihd) (2) adding methyl alcohol; (3) allowing the mixture to stand at room temperature in a closed vessel until it has become a gelatinated mass; and (4:) Working such mass on rolls or in a heated press, or otherwise, substantially as described.

3. The process of making lastic compounds of acetyl cellulose consisting in (l) incorporating ethyl para toluol-suphonamid and triphenyl phosphate with an acetyl cellulose which is soluble in acetone; (2) adding one or more of the group of the hereinbefore-described alcohols (ethyl alcohol, methyl alcohol); (3) allowingthe mixture to stand at room temperature in a closed essel until it has become a gelatinated mass; and (4) working such mass on rolls or m a heated press, or otherwise,

heated press, or otherwise, substantially as described. 4. The process of making plastic compounds of acetyl cellulose consisting in (l) incorporating ethyl ara toluol-sulphonamid and triphenyl phosp ate with an acetyl cellulose which is soluble in acetone; (2) adding methyl alcohol; (3) allowing the mixture to stand at room temperature in a closed vessel until it has become a gelatinated mass; and (4) working such mass on rolls or in a substantially as described.

WILLIAM G. LINDSAY. Witnesses:

IRVING M. WEISS,

J. E. HINDON HYDE. 

